How can I effectively address and improve a weedy lawn without the use of chemicals?

To effectively address and improve a weedy lawn without using chemicals, you can start by manually removing weeds by hand or using tools like a weeding tool or hoe. You can also improve the health of your lawn by mowing at the correct height, watering deeply but infrequently, and overseeding with grass seeds to fill in bare spots. Additionally, aerating the soil and adding organic matter like compost can help promote healthy grass growth and outcompete weeds.